Today I would like to compare a activescaffold rails 3.0 controller index action waterfall chart with one of a rails 3.1 controller.
You will see a big difference in these charts because of the asset pipeline feature. Asset pipeline is merging your js and css assets into one big file which improves your webperformance because of reduced http requests.
In addition I m using css data-uri feature for background images. Please note that ie6 and ie7 do not support data-uris.

Rails 3.0 waterfall

Rails 3.1 waterfall